Intravascular catheter having an expandable incising portion for incising atherosclerotic material located in a blood vessel

ABSTRACT

A method for performing balloon catheterization of a zone of attention is provided. An intravascular device has an expandable portion secured to a distal end of a catheter tube. The expandable portion has a number of struts, at least one having an incising element extending perpendicular therefrom. The intravascular device is placed within a person&#39;s vascular system and moved to the zone of attention where the expandable portion is expanded and manipulated along the zone of attention to score the atherosclerotic material located in the blood vessel. Subsequently, a balloon catheter device is moved to the zone of attention and inflated to compress or fragment the scored atherosclerotic material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No.15/481,552, which is a continuation of application Ser. No. 13/613,914,filed Sep. 13, 2012 and now issued as U.S. Pat. No. 9,615,848 dated Apr.11, 2017, which claims the benefit of U.S. Provisional Application No.61/534,018, filed Sep. 13, 2011, the disclosures of all of which arehereby incorporated by reference in their entirety.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates in general to intravascular catheters, such ascan be used during minimally invasive surgical procedures. Inparticular, this invention relates to an intravascular catheter havingan expandable incising portion.

Atherosclerosis is a chronic condition in which atheromatous plaqueaccumulates on the inner walls of a blood vessel. As a result, the bloodvessel walls can become inflamed and, over time, may harden to formatherosclerotic lesions that cause a narrowing of the vessel lumen. Insevere cases, the atherosclerotic lesions can rupture and induce theformation of thrombus (i.e., blood clots), which can prevent blood flowthrough the narrowed vessel lumen.

There are known procedures and devices for treating or otherwisereducing the risks associated with atherosclerosis. For example, anangioplasty is a procedure in which a balloon catheter is inserted intoa narrowed region of the vessel lumen via a delivery catheter. Theballoon catheter includes a flexible tube having an inflatable balloonat an end thereof. Once positioned in the narrowed region, the balloonis inflated in order to dilate the narrowed vessel lumen. The pressurein the balloon is generally sufficient to compress the accumulatedplaque. However, compressing the atherosclerotic material requires theuse of relatively high inflation pressures. Such angioplasty proceduresare typically performed by inflating a balloon to a pressure in therange of 10-20 atmospheres. These high inflation pressures place astrain on the blood vessel walls and on the tissue surrounding the bloodvessel, which can result in damage.

In some cases, it would be desirable to score the atheroscleroticmaterial so as to break the surface tension and permit compression to beperformed at lower pressures. In some cases, it would be desirable toscore the atherosclerotic material so as to fragment the atheroscleroticlesions or permit fragmentation of the same during subsequentangioplasty. Thus, it would be desirable to provide an intravascularcatheter having an expandable portion that can be selectively controlledby a user and adapted to create incisions in atherosclerotic material tofacilitate the compression or fragmentation of the atheroscleroticmaterial during a subsequent angioplasty procedure.

This invention relates to an intravascular catheter device for useduring a surgical procedure. The catheter device includes a cathetertube having an expandable portion with a plurality of struts eachdefining an outer surface. The expandable portion is operable between aclosed position, wherein the expandable portion has a first diameter,and an opened position, wherein the expandable portion has a seconddiameter that is larger than the first diameter. An incising element isprovided on the outer surface of at least one of the struts. Theincising element has a sharpened edge that extends outwardly in a radialdirection from the outer surface of the strut for creating an incisionin atherosclerotic material located within a blood vessel when theexpandable portion is in the opened position.

The expandable portion, particularly the incising element and sharpenededge, may be configured to prepare the blood vessel for subsequentangioplasty. The intravascular catheter device may be configured tofacilitate the scoring of the atherosclerotic material, which may breakthe surface tension in the atherosclerotic material and provide forsubsequent the compression thereof by angioplasty at reduced pressuresrelative to traditional procedures. After scoring the atheroscleroticmaterial with the intravascular catheter device, equivalent or improvedcompression may be achieved at balloon inflation pressures of 1 to 5atmospheres in exemplary embodiments, though any pressure or anypressure range is contemplated. Scoring the atherosclerotic materialwith the intravascular catheter device may also facilitate thefragmentation of the atherosclerotic material when scoring or duringsubsequent angioplasty.

Various aspects of this invention will become apparent to those skilledin the art from the following detailed description of the preferredembodiments, when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a catheter device that includes a handleassembly and a catheter tube having an expandable incising portion, inaccordance with a first embodiment of this invention.

FIG. 2 is a cross-sectional side view of the handle assembly taken alongsection line 2-2 shown in FIG. 1 when the catheter device is in a firstoperating mode.

FIG. 3 is an enlarged cross-sectional side view of the catheter tubetaken along section line 3-3 shown in FIG. 1 illustrating the expandableincising portion disposed within a blood vessel.

FIG. 4 is a cross-sectional end view of the expandable incising portiontaken along section line 4-4 shown in FIG. 3.

FIG. 5 is a cross-sectional side view of the handle assembly taken alongsection line 2-2 shown in FIG. 1 when the catheter device is in a secondoperating mode.

FIG. 6 is an enlarged cross-sectional side view of the catheter tubetaken along section line 3-3 shown in FIG. 1 illustrating the expandableincising portion in an opened position.

FIG. 7 is a cross-sectional end view of the expandable incising portiontaken along section line 7-7 shown in FIG. 6.

FIG. 8 is an enlarged side view of a catheter tube having an expandableincising portion, in accordance with a second embodiment of thisinvention.

FIG. 9 is a side view of the catheter tube shown in FIG. 8 illustratingthe expandable incising portion in an opened position.

FIG. 10 is a cross-sectional end view of the expandable incising portiontaken along section line 10-10 shown in FIG. 9.

FIG. 11 is an enlarged side view of a catheter tube having an expandableincising portion, in accordance with a third embodiment of thisinvention.

FIG. 12 is a side view of the catheter tube shown in FIG. 11illustrating the expandable incising portion in an opened position.

FIG. 13 is an end view of the catheter tube as shown in FIG. 12.

FIG. 14 is an enlarged side view of a catheter tube having an expandableincising portion, in accordance with a fourth embodiment of thisinvention.

FIG. 15 is a side view of the catheter tube shown in FIG. 14illustrating the expandable incising portion in an opened position.

FIG. 16 is an end view of the catheter tube as shown in FIG. 15.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, there is illustrated in FIG. 1 a catheterdevice, indicated generally at 10, in accordance with this invention.The illustrated catheter device 10 is configured to treat or reduce therisks associated with atherosclerosis. In general, the catheter device10 includes an expandable incising portion that can be inserted into ablood vessel and expanded to create incisions in atheroscleroticmaterial that has accumulated on inner walls of the blood vessel. Theincisions facilitate the compression or fragmentation of theatherosclerotic material during a subsequent angioplasty or atherectomyprocedure. The catheter device 10, and the incisions created thereby,may facilitate equivalent or improve compression of the atheroscleroticmaterial to be achieved at pressures of 1-5 atmospheres, as compared tothe standard pressures of 10-20 atmospheres. More specifically, thecatheter device, and the incisions created thereby, may be configured toincise the atherosclerotic material by breaking the surface tension inthe atherosclerotic material. By breaking the surface tension, adequatecompression may be realized at reduced inflation pressures duringsubsequent angioplasty. Further, the catheter device 10, and theincisions created thereby, may facilitate the fragmentation of theatherosclerotic material during the scoring or during subsequentangioplasty. In exemplary embodiments, the angioplasty may be performedby a balloon catheter device having an angioplasty balloon configured tobe moved between an inflated state and a deflated state. Although thecatheter device 10 will be described and illustrated in the context oftreating atherosclerosis, it should be appreciated that the catheterdevice 10 can be used in any desired environment and for any desiredpurpose.

Referring now to FIGS. 1 and 2, the illustrated catheter device 10includes a handle assembly, indicated generally at 20. The illustratedhandle assembly 20 includes an elongated, cylindrical handle body 21.The handle body 21 may alternatively have any other shape that issuitable for easy handling by a surgeon. Further, the handle body 21 canbe made from any suitably rigid material including, but not limited to,stainless steel or polymers.

As shown in FIG. 2, the illustrated handle body 21 defines an internalchamber 22. A passage 23 extends into an end portion of the handle body21 for communication with the internal chamber 22. The handle body 21further includes a slot 24 that extends through a side wall thereof forcommunication with the internal chamber 22. The illustrated slot 24 mayhave any length or width as desired. As shown in FIG. 1, an indicator24A may be provided on the handle body 21 adjacent to the slot 24. Forexample, the indicator 24A can be a visual scale or any other indicatingmeans, the purpose of which will be explained below.

The illustrated handle assembly 20 also includes a control member 25that is supported on the handle body 21 for sliding movement within theslot 24. For example, the control member 25 is movable between a forwardposition (shown in FIG. 2), a rearward position (shown in FIG. 5), orany position therebetween, which will be further explained below. Asshown in FIG. 2, the illustrated control member 25 includes a baseportion 26 that is disposed within the internal chamber 22 of the handlebody 21. The base portion 26 may define an outer cross-sectional shapethat generally corresponds with a cross-sectional shape of the internalchamber 22, although such is not required. Alternatively (or inaddition), the control member 25 may be movably supported on the handlebody 21 by a bearing, a bushing, a guide rail, or any other structuralmeans. In other embodiments, the control member 25 may be supported forrotational movement, pivotal movement, or any other type of movementrelative to the handle body 21, the purpose of which will becomeapparent below. The visual indicator 24A, described above, is configuredto identify the relative position of the control member 25 with respectto the handle body 21.

The illustrated handle assembly 20 also includes a locking mechanism 27that is configured to temporarily secure the control member 25 in adesired position, although such is not required. As shown in FIG. 2, theillustrated locking mechanism 27 includes a plurality of protrusionsthat are spaced apart from one another along an inner surface of theslot 24. The control member 25 frictionally engages the protrusions tohold the control member 25 in the desired position. Alternatively, thelocking mechanism 27 may be a threaded fastener, a pivotal latch, apush-button release, or any other mechanism that is configured to securethe control member 25 in a desired position.

Referring now to FIGS. 1 through 3, the illustrated catheter device 10also includes a catheter tube 30 that extends from the handle assembly20. The catheter tube 30 is an elongated, flexible member having aproximal end that is secured to the handle assembly 20 and a distal endthat extends therefrom. The catheter tube 30 can be made from anybiocompatible material including, but not limited to, polyvinyl,polyethylene, nitinol, or stainless steel. Further, the catheter tube 30can have any outer diameter, length, or wall thickness.

As shown in FIG. 2, the proximal end of the catheter tube 30 is securedto the handle body 21 and communicates with the internal cavity 22through the passage 23. The catheter tube 30 may be secured to thehandle body 21 using a flanged connection, a fused connection, anadhesive, a press-fit connection, a threaded connection, or any othersecuring means. Alternatively, the catheter tube 30 may be secured tothe handle body 21 using a connector or any other type of attachmentdevice.

As shown in FIGS. 1 and 3, an expandable portion 32 is provided on thedistal end of the catheter tube 30. The illustrated expandable portion32 is a cylindrical member having a longitudinal axis. The expandableportion 32 can be made from a generally resilient material that is ableto flex between various positions, such as polyvinyl, polyethylene,nitinol, or stainless steel. The expandable portion 32 can be secured tothe catheter tube 30 in any manner including, but not limited to, afused connection, an adhesive, a press-fit connection, a threadedconnection, or any other securing means. Alternatively, the expandableportion 32 can be integrally formed from the catheter tube 30. Further,the expandable portion 32 can have any outer diameter, length, or wallthickness.

The illustrated expandable portion 32 has a pair of struts 34A and 34B.The illustrated struts 34A and 34B are separated by a pair oflongitudinally extending slits 35A and 35B that extend through sidewalls of the expandable portion 32. As shown in FIG. 4, the slits 35Aand 35B are equally spaced apart from one another around thecircumference of the expandable portion 32 such that the struts 34A and34B have the same circumferential widths, although such is not required.The struts 34A and 34B may have any length, circumferential width, orcross-sectional shape as desired.

As shown in FIGS. 3 and 4, the illustrated expandable portion 32 alsoincludes a pair of incising elements 36 that are respectively providedalong outer surfaces of the struts 34A and 34B. The incising elements 36can be atherotomes or other incising members having arcuate shapedsharpened edges, for example, that are configured to create incisions inatherosclerotic material as will be explained below. The illustratedincising elements 36 extend parallel with the longitudinal axis of theexpandable portion 32 and outwardly in a radial direction therefrom. Theincising elements 36 are equally spaced apart from one another aroundthe circumference of the expandable portion 32. The expandable portion32 may, however, have any number or configuration of incising elements36 provided around the circumference thereof. Further, the incisingelements 36 can have any cross-sectional shape, longitudinal length, orheight and can be made from any suitable material including, but notlimited to, tempered steel, stainless steel, high carbon steel, orceramics. The incising elements 36 can be molded with the struts 34A and34B or may otherwise be secured thereto in any manner such as, forexample, using a welded or soldered connection, an adhesive, or anyother fastening means.

The expandable portion 32, particularly (without limitation) theincising elements 36 and the sharpened edges, may be configured toprepare the atherosclerotic material 54 located in the blood vessel 50for subsequent angioplasty. The catheter device 10 may be configured tofacilitate the scoring of the atherosclerotic material 54 and thesubsequent the compression thereof by angioplasty at reduced pressuresrelative to traditional procedures. After scoring the atheroscleroticmaterial 54 with the intravascular catheter device 10, equivalent orimproved compression may be achieved at balloon inflation pressures of 1to 5 atmospheres, though any pressure or any pressure range iscontemplated. More specifically, the expandable portion 32, particularly(without limitation) the incising elements 36 and the sharpened edges,may be configured to break the surface tension in the atheroscleroticmaterial 54 which may facilitate adequate compression at the reducedinflation pressures. Scoring the atherosclerotic material 54 with thecatheter device 10 may also facilitate the fragmentation of theatherosclerotic material 54 during the scoring or during subsequentangioplasty.

The distal end of the expandable portion 32 may optionally include a tipmember 38. The illustrated tip member 38 has a generally conical shapethat facilitates insertion of the catheter tube 30 within a blood vessel50 (see FIGS. 3 and 4) and subsequent travel therethrough. The tipmember 38 may, however, have any desired shape. An aperture may axiallyextend through the tip member 38, the purpose of which will be explainedbelow. The tip member 38 can be integrally formed with the expandableportion 32 or may be secured thereto, such as with an adhesive or thelike. Further, the tip member 38 can be made from any biocompatiblematerial including, but not limited to, polyvinyl, polyethylene,nitinol, stainless steel, or polyether block amide.

As shown in FIGS. 2 through 4, the illustrated catheter device 10 alsoincludes an inner sleeve 40, although such is not required. The innersleeve 40 is a flexible, tubular member that is supported for slidingmovement within the catheter tube 30, the purpose of which will beexplained below. The inner sleeve 40 can be made from any biocompatiblematerial including, but not limited to, polyvinyl, polyethylene,nitinol, stainless steel, or a woven material. Further, the inner sleeve40 can have any outer diameter, length, or wall thickness. The innersleeve 40 need not be a tubular member but may alternatively be a solidwire, a braided wire, or the like.

As shown in FIG. 2, a proximal end of the inner sleeve 40 extends fromthe catheter tube 30 and into the internal chamber 22 of the handle body21. The proximal end of the inner sleeve 40 is secured to the baseportion 26 of the control member 25 for sliding movement therewith, thepurpose of which will be explained below. The inner sleeve 40 can besecured to the base portion 26 by a flanged connection, a fusedconnection, an adhesive, a threaded connection, or any other securingmeans.

As shown in FIG. 3, the inner sleeve 40 extends through an entire lengthof the catheter tube 30. A distal end of the inner sleeve 40 that isopposite the handle assembly 20 is secured to the tip member 38, whichis in turn secured to the expandable portion 32. The inner sleeve 40 maybe secured to the tip member 38 in any manner including, but not limitedto, a fused connection, an adhesive, a fastener, or the like.

Referring back to FIGS. 1 and 2, the illustrated catheter device 10 alsoincludes a protective sheath 42 that is supported for sliding movementalong an outer surface of the catheter tube 30, although such is notrequired. The protective sheath 42 can be made from any biocompatiblematerial including, but not limited to, polyvinyl, polyethylene,nitinol, or stainless steel. Further, the protective sheath 42 can haveany outer diameter, length, or wall thickness. The purpose of theprotective sheath 42 will be explained below.

The illustrated protective sheath 42 includes a flange 44 thatfacilitates sliding movement of the protective sheath 42 relative to thecatheter tube 30. The illustrated flange 44 is an annular member that islocated at an end of the protective sheath 42 nearest the handleassembly 20. The flange 44 can be integrally formed with the protectivesheath 42 or may otherwise be secured thereto in any manner, such aswith an adhesive or the like. It should be appreciated that the flange44 can have any shape or may alternatively be configured in any mannerto accomplish the functions described herein and below.

The operation of the catheter device 10 will now be described withreference to FIGS. 1 through 7. Referring initially to FIGS. 1 through4, the catheter device 10 is illustrated in a first operating mode. Inthe first operating mode, the control member 25 on the handle assembly20 is located in the forward position relative to the handle body 21.The inner sleeve 40 fully extends into the catheter tube 30 such thatthe expandable portion 32 is in a closed position, as shown in FIGS. 3and 4. In the closed position, the struts 34A and 34B are generallyparallel with one another and with the inner sleeve 40. The slits 35Aand 35B (illustrated by the dashed lines in FIG. 3) remain in agenerally closed configuration. As such, the expandable portion 32defines an initial diameter D1, which is generally the same diameter asthe remaining length of the catheter tube 30. The initial diameter D1 ofthe expandable portion 32 may, however, be any desired dimension.

When the catheter device 10 is in the first operating mode, the distalend of the catheter tube 30 can be percutaneously inserted into a bloodvessel 50, as shown in FIGS. 3 and 4. The illustrated catheter tube 30is then advanced through the blood vessel 50 along a guide wire 52,which extends through the catheter device 10. For example, the guidewire 52 may fully extend through the inner sleeve 40, into the internalchamber 22 of the handle body 21, and exit a rear end of the handleassembly 20 (see FIG. 2). The catheter tube 30 is advanced along theguide wire 52 until the expandable portion 32 is positioned in anarrowed region of the blood vessel 50 caused by atheroscleroticmaterial 54. Alternatively, the catheter tube 30 can be inserted intothe blood vessel 50 and guided therethrough by a delivery catheter (notshown) or any other suitable procedure. During insertion and advancementof the catheter tube 30 through the blood vessel 50, the optionalprotective sheath 42 is preferably positioned over the expandableportion 32, thereby preventing the incising elements 36 from coming intocontact with inner walls of the blood vessel 50.

Once the expandable portion 32 is positioned in the narrowed region ofthe blood vessel 50, the incising elements 36 can be exposed by slidingthe protective sheath 42 back from the distal end of the catheter tube30, as indicated by the direction arrows in FIG. 3. The illustratedprotective sheath 42 can be moved in this manner by pulling the flange44 towards the handle assembly 20, which is indicated by the directionarrows in FIG. 2.

Referring now to FIGS. 5 through 7, the catheter device 10 isillustrated in a second operating mode. To achieve the second operatingmode, the control member 25 is moved from the forward position to therearward position, as indicated by the direction arrow in FIG. 5. As thecontrol member 25 is moved to the rearward position, the inner sleeve 40is drawn within the catheter tube 30 thereby reducing the relativelength of the inner sleeve 40 with respect to the catheter tube 30. Thedistal end of the inner sleeve 40 is attached to the tip member 38, asdescribed above, causing the expandable portion 32 to become axiallycompressed between the tip member 38 and the distal end of the cathetertube 30. As a result, the struts 34A and 34B bow or expand outwardly ina generally arcuate fashion thereby defining an opened position. In theopened position, the expandable portion 32 defines a second diameter D2that is larger than the initial diameter D1 when the expandable portion32 is in the closed position. As shown in FIG. 6, the incising elements36 are respectively positioned along the radially outer most surfaces ofthe struts 34A and 34B. Further, the outer most surfaces of the struts34A and 34B may define a generally flat portion along a length thereofin the opened position, the purpose of which will be explained below,although such is not required. It should be appreciated that the struts34A and 34B can have any lengths such that the expandable portion 32 canachieve a desired overall second diameter D2 in the opened position.

During operation of the catheter device 10, the second diameter D2 canbe increased or decreased by selective movement of the control member 25between the forward and rearward positions. For example, a larger seconddiameter D2 can be achieved by moving the control member 25 furthertowards the rearward position. Conversely, a smaller second diameter D2can be achieved by moving the control member 25 further towards theforward position. The visual indicator 24A can be used to identify theinstantaneous second diameter D2 of the expandable portion 32.Alternatively (or in addition), the struts 34A and 34B may be biased inthe opened position so as to automatically expand outwardly to thesecond diameter D2 when the protective sheath 42 is slid back from theexpandable portion 32. As such, sliding movement of the protectivesheath 42 relative to the struts 34A and 34B can be used to selectivelycontrol the second diameter D2. In this configuration, the inner sleeve40 and the movable components of the handle assembly 20 may not benecessary.

When the catheter device 10 is in the second operating mode, theexpandable portion 32 can be pulled along the guide wire 52 through thenarrowed region of the blood vessel 50. This can be accomplished bypulling on the handle assembly 20. In doing so, the incising elements 36engage the atherosclerotic material 54 and create longitudinal incisions56 therein. As shown in FIGS. 6 and 7, the outer surface area of thearcuate shaped struts 34A and 34B, which is adjacent to the incisingelement 36, is configured to ride along a surface of the atheroscleroticmaterial 54, thereby limiting the depth of the incisions 56 andpreventing the incising members 36 from cutting the walls of the bloodvessel 50. The expandable portion 32 can be moved any distance along theguide wire 52 to create incisions 56 having any desired length. Afterthe incisions 56 are made in the atherosclerotic material 54, thecatheter device 10 can be returned to the first operating mode (shown inFIGS. 1 through 4) by moving the control member 25 to the forwardposition. In doing so, the expandable portion 32 returns to the closedposition. The protective sheath 42 can be slid over the expandableportion 32 and the catheter tube 30 may be removed from the blood vessel50.

Alternatively, the catheter device 10 can be used to create additionalincisions 56 in the atherosclerotic material 54. For example, after thecatheter device 10 has been returned to the first operating mode, theexpandable portion 32 can be relocated within the narrowed region of theblood vessel 50. The catheter tube 30 can then be rotated within theblood vessel 50 by rotating the handle assembly 20 so as to align theincising elements 36 with other portions of the atherosclerotic material54. The previous steps can then be repeated any number of times to makemultiple passes through the narrowed region of the blood vessel 50 andcreate additional incisions in the atherosclerotic material 54.

Thus, it should be appreciated that the illustrated catheter device 10is advantageous in many respects. In one example, the second diameter D2of the expandable portion 32 can be selectively controlled by operationof the handle assembly 20 or by sliding movement of the protectivesheath 42. This enables the catheter device 10 to be adapted for use inblood vessels 50 of different sizes or varying diameters. In anotherexample, the illustrated catheter device 10 can apply varying magnitudesof radial forces to the atherosclerotic material 54 by controlling theamount of force being applied to the control member 25 on the handleassembly 20. This enables the catheter device 10 to generate sufficientradial force to create incisions 56 in atherosclerotic material 54 whilereducing the potential for tearing the walls of the blood vessel 50. Inyet another example, the catheter device 10 can be used to make anynumber of passes during a single procedure to make multiple incisions 56in atherosclerotic material 54 of varying lengths and shapes.

Referring now to FIGS. 8 through 10, there is illustrated a cathetertube 130 having an expandable portion 132, in accordance with a secondembodiment of this invention. The catheter tube 130 and the expandableportion 132 may include any structural features as described andillustrated above in the previous embodiment, although such is notrequired. Similar features have been numbered with common referencenumerals but have been increased by 100 (i.e., 110, 120, 130, etc.). Itshould be appreciated that similar features are structured similarly,operate similarly, and/or have the same function unless otherwiseindicated by the drawings or this specification.

For example, the catheter tube 130 may extend from a handle assembly(not shown) as described above in the first embodiment. The expandableportion 132 is provided on a distal end of the catheter tube 130 and mayinclude a tip member 138. The catheter tube 130 may also include aninner sleeve 140 and a protective sheath (not shown), which is alsodescribed above in the first embodiment.

In the illustrated embodiment, however, the expandable portion 132includes four struts 134A, 1348, 134C, and 134D that are respectivelyseparated by four longitudinally extending slits 135A, 1358, 135C, and135D. The illustrated struts 134A, 134B, 134C, and 134D each include anincising element 136, although such is not required. It should beappreciated that the expandable portion 132 may have any number orconfiguration of struts and incising elements as desired.

As shown in FIG. 8, the illustrated expandable portion 132 furtherincludes recessed portions 160 that respectively extend into the outersurfaces of the struts 134A, 1348, 134C, and 134D. For example, thestruts 134A, 1348, 134C, and 134D can be slightly bowed inwardly towardthe inner sleeve 140 when in the closed position or, alternatively, mayhave a reduced thickness along a central portion thereof to create therecessed portions 160. The illustrated incising elements 136 arerespectively disposed within the recessed portions 160. Thus, when thecatheter tube 130 is inserted into a blood vessel, as described above,the recessed portions 160 help to prevent the incising elements 136 fromcoming into contact with inner walls of the blood vessel. On the otherhand, when the expandable portion 132 is expanded to an opened position,as explained below, the incising elements 136 become exposed from therecessed portions 160. It should be appreciated that the recessedportions 160 can eliminate or reduce the need for the protective sheath(not shown). The guide wire 152 may extend through the entire device.

The expandable portion 132 can be operated between a closed position(shown in FIG. 8) and an opened position (shown in FIGS. 9 and 10) byselective movement of the inner sleeve 140 relative to the catheter tube130, as described above in the first embodiment. Alternatively (or inaddition), the struts 134A, 1348, 134C, and 134D can be biased in theopened position. In such an embodiment, the protective sheath (notshown) can be used to effect movement of the expandable portion 132between the closed position and the opened position.

Referring now to FIGS. 11 through 13, there is illustrated a cathetertube 230 having an expandable portion 232, in accordance with a thirdembodiment of this invention. The catheter tube 230 and the expandableportion 232 may include any structural features as described andillustrated above in the previous embodiments, although such is notrequired. Similar features have been numbered with common referencenumerals but have been increased by 200 (i.e., 210, 220, 230, etc.). Itshould be appreciated that similar features are structured similarly,operate similarly, and/or have the same function unless otherwiseindicated by the drawings or this specification.

For example, the catheter tube 230 may extend from a handle assembly(not shown) as described above in the first embodiment. The expandableportion 232 is provided on a distal end of the catheter tube 230 andincludes a pair of struts 234A and 234B that are separated by a pair oflongitudinally extending slits 235A and 235B. The catheter tube 230 mayalso include a tip member 238, an inner sleeve 240, and a protectivesheath (not shown), which is described above in the first embodiment.The guide wire 252 may extend through the entire device.

In the illustrated embodiment, however, the expandable portion 232includes a first pair of weakened regions 237A, 237B and a second pairof weakened regions 239A, 239B that are respectively located at oppositeends of the struts 234A and 234B. The illustrated weakened regions 237A,237B and 239A, 239B are formed by enlarged apertures that extend throughside walls of the expandable portion 232 that function as hinges. Theweakened regions 237A, 237B and 239A, 239B may help reduce the amount ofbending stress in the side walls of the expandable portion 232 when thestruts 234A and 234B are moved to an opened position. The struts 234Aand 234B may include any number or configuration of weakened regions.Further, it should be appreciated that any of the other embodiments inthis disclosure may also include weakened regions 237A, 237B and 239A,239B.

The illustrated struts 234A and 234B remain generally flat alongrespective lengths thereof in both a closed position (shown in FIG. 11)and an opened position (shown in FIGS. 12 and 13) so as to form an apex,although such a configuration is not required. The incising elements 236are provided along the generally flat portion of the respective struts234A and 234B. As such, the incising elements 236 may also function asstiffening members for increasing the strength of the struts 234A and234B. Further, this configuration can reduce the amount of stress in theconnection between the incising elements 236 and the struts 234A and234B, which may otherwise be caused by bowing of the struts 234A and234B.

As shown in FIG. 12, end portions of the incising elements 236 mayextend beyond the apex that is formed by each of the respective struts234A and 234B. This configuration can increase the effective height ofthe incising elements 236 when the expandable portion 232 is in theopened position. As such, the incising elements 236 may have a reducedheight when the expandable portion 232 is in the closed position, whichmay eliminate the need for the protective sheath (not shown).

The expandable portion 232 can be operated between the closed positionand the opened position by selective movement of the inner sleeve 240relative to the catheter tube 230, as described above in the firstembodiment. Alternatively (or in addition), the struts 234A and 234B canbe biased in the opened position. In such an embodiment, the protectivesheath (not shown) can be used to effect movement of the expandableportion 232 between the closed position and the opened position.

Referring now to FIGS. 14 through 16, there is illustrated a cathetertube 330 having an expandable portion 332, in accordance with a fourthembodiment of this invention. The catheter tube 330 and the expandableportion 332 may include any structural features as described andillustrated above in the previous embodiments, although such is notrequired. Similar features have been numbered with common referencenumerals but have been increased by 300 (i.e., 310, 320, 330, etc.). Itshould be appreciated that similar features are structured similarly,operate similarly, and/or have the same function unless otherwiseindicated by the drawings or this specification.

For example, the catheter tube 330 may extend from a handle assembly(not shown) as described above in the first embodiment. The expandableportion 332 is provided on a distal end of the catheter tube 330 and mayinclude a tip member 338. The catheter tube 330 may also include aninner sleeve 340 that is attached to the tip member 338 and a protectivesheath (not shown), which is also described above in the firstembodiment. The guide wire 352 may extend through the entire device.

In the illustrated embodiment, however, the expandable portion 332includes a pair of struts 334A and 334B that are supported thereon in acantilevered manner (i.e., not attached to one another or to the tipmember 338 at their distal ends), the purpose of which will be explainedbelow. The struts 334A and 334B are separated by a pair oflongitudinally extending slits 335A and 335B that extend from the end ofthe expandable portion 332. A pair of incising elements 336 isrespectively provided along outer surfaces of the struts 334A and 334B.It should be appreciated, however, that the expandable portion 332 mayhave any number or configuration of struts and incising elements asdesired.

As shown in FIGS. 15 and 16, the illustrated struts 334A and 334B aresupported on the expandable portion 332 so that they can be splayed openin a Y-shaped configuration. For example, the struts 334A and 334B canbe splayed open by drawing the inner sleeve 340 within the catheter tube330, as described above in the first embodiment. In doing so, the tipmember 338 slides along the inner surfaces of the struts 334A and 334Band pivots them outwardly. Alternatively (or in addition), the struts334A and 334B can be biased in the splayed open position. In such anembodiment, the protective sheath (not shown) can be used to effectmovement of the expandable portion 332 between a closed position and thesplayed open position.

The struts 334A and 334B remain generally flat along their respectivelengths in both a closed position (shown in FIG. 14) and the splayedopen position, although such is not required. As such, the incisingelements 336 may also function as stiffening members for increasing thestrength of the struts 334A and 334B. Further, this configuration canreduce the amount of stress in the connection between the incisingelements 336 and the struts 334A and 334B, which may otherwise be causedby bowing of the struts 334A and 334B.

As shown in FIG. 15, end portions of the incising elements 336 mayextend beyond the distal ends of the respective struts 334A and 334B.This configuration can increase the effective height of the incisingelements 336 when the expandable portion 332 is in the splayed openposition. As such, the incising elements 336 may have a reduced heightwhen the expandable portion 332 is in the closed position, which mayeliminate the need for the protective sheath (not shown).

The principle and mode of operation of this invention have beenexplained and illustrated in its preferred embodiments. However, it mustbe understood that this invention may be practiced otherwise than asspecifically explained and illustrated without departing from its spiritor scope.

What is claimed is:
 1. A method of performing balloon catheterization ofa zone of attention in a person's vascular system, wherein said zone ofattention is located in a blood vessel which comprises atheroscleroticmaterial, said method comprising the steps of: providing anintravascular device comprising: a catheter tube, an expandable portionsecured to a distal end of said catheter tube and comprising a pluralityof struts operable between a collapsed position and an expandedposition, an incising element provided on and extending substantiallyperpendicular from at least one of the struts; providing a ballooncatheter device configured to be operable between an inflated and adeflated state; locating the intravascular device at or near an edge ofthe zone of attention; placing the expandable portion in the expandedposition; manipulating the intravascular device along the zone ofattention so as to incise the atherosclerotic material; locating theangioplasty balloon at the zone of attention; and inflating theangioplasty balloon.
 2. The method of claim 1 wherein: the angioplastyballoon is inflated at a pressure not exceeding 5 atmospheres.
 3. Themethod of claim 2 wherein: the inflation of the angioplasty ballooncauses the atherosclerotic material to be fragmented.
 4. The method ofclaim 2 wherein: the inflation of the angioplasty balloon causes theatherosclerotic material to be compressed.
 5. The method of claim 1further comprising the steps of: placing the expandable portion in thecollapsed position; inserting the intravascular device into the person'svascular system; navigating the intravascular device at or near the zoneof attention; and removing the intravascular device from the person'svascular system.
 6. The method of claim 5 further comprising the stepsof: placing the angioplasty balloon in the deflated position; insertingthe angioplasty balloon into the person's vascular system; navigatingthe angioplasty balloon at or near the zone of attention; and removingthe angioplasty balloon from the person's vascular system.
 7. The methodof claim 1 wherein: the intravascular device further comprises aflexible inner sleeve disposed within the catheter tube, wherein saidinner sleeve is supported for sliding movement within the catheter tubeand is configured to fit atop a guide wire.
 8. The method of claim 7wherein: the incising elements extend longitudinally along at least aportion of the at least one strut and comprises a sharpened edge locatedalong an upper edge thereof such that the sharpened edge extends inparallel with a longitudinal axis of the expandable portion when theexpandable portion is in the closed position.
 9. The method of claim 1wherein: the intravascular device is manipulated along substantially theentire length of the zone of attention.
 10. The method of claim 1wherein: the step of manipulating the intravascular device along thezone of attention is repeated at least once.
 11. The method of claim 1wherein: the step of placing the expandable portion in the expandedposition requires the incising elements to protrude into theatherosclerotic material without contacting the blood vessel wall. 12.The method of claim 1 wherein: the zone of attention is located in aperipheral artery.
 13. A method of performing balloon catheterization ofa zone of attention in a person's vascular system, wherein said zone ofattention is located in a blood vessel which comprises atheroscleroticmaterial, said method comprising the steps of: providing anintravascular device comprising: a catheter tube, a flexible innersleeve disposed within the catheter tube and supported for slidingmovement within the catheter tube, an expandable portion secured to adistal end of said catheter tube and comprising a plurality of strutsoperable between a collapsed position and an expanded position, and anincising element provided on substantially the midline of and extendingsubstantially perpendicular from at least one of the struts; providing aballoon catheter device configured to be operable between an inflatedand a deflated state; preparing the intravascular device for insertioninto the person's vascular system; inserting the intravascular deviceinto the person's vascular system; locating the intravascular device ator near the zone or attention; preparing the intravascular device fortreatment of the zone of attention; treating the zone of attention withthe intravascular device; preparing the balloon catheter device forinsertion into the person's vascular system; inserting the ballooncatheter device into the person's vascular system; locating the ballooncatheter device at or near the zone of attention; and treating the zoneof attention with the balloon catheter device.
 14. The method of claim13 wherein: the balloon catheter device comprises an angioplastyballoon.
 15. The method of claim 13 wherein: the step of treating thezone of attention with the balloon catheter device comprises inflatingthe balloon catheter to an effective pressure sufficient to open theblood vessel using between 1 and 5 atmospheres of pressure.
 16. Themethod of claim 15 wherein: the step of preparing the balloon catheterdevice for insertion into the person comprises placing the ballooncatheter device in the deflated state.
 17. The method of claim 13wherein: the step of treating the zone of attention with theintravascular device comprises moving the intravascular device along atleast a portion of the zone of attention.
 18. The method of claim 17wherein: the step of preparing the intravascular device for insertioninto the person comprises placing the intravascular device in thecollapsed position.
 19. The method of claim 13 further comprising thesteps of: rotating the intravascular device; and retracting theintravascular device along the zone of attention a second time so as toincise a different portion of the atherosclerotic material.
 20. A methodof performing balloon catheterization of a zone of attention in aperson's vascular system, wherein said zone of attention is located in ablood vessel which comprises atherosclerotic material, said methodcomprising the steps of: providing an intravascular device comprising: acatheter tube, a flexible inner sleeve disposed within the catheter tubeand supported for sliding movement within the catheter tube, anexpandable portion secured to a distal end of said catheter tube andcomprising a plurality of struts operable between a collapsed positionan expanded position, and an incising element provided on and extendingsubstantially perpendicular from substantially the midline of theproximal half of at least one of the struts; providing a ballooncatheter device configured to be operable between an inflated and adeflated state; locating the intravascular device at or near an end ofthe zone of attention; placing the expandable portion in the expandedposition; retracting the intravascular device along substantially theentire zone of attention so as to incise the atherosclerotic material;locating the angioplasty balloon at the zone of attention; and inflatingthe angioplasty balloon at a pressure between 1 and 5 atmospheres.